It will allow me to get user data from nodebb? I am a little rusty on Oauth2 but if I am a provider don't I already need to have user data or does the oauth plugin make nodebb the provider?

Hi I am working on a site that has an existing nodebb forum and we are looking to add features to the site that require a user to have an account. I know nodebb doesn't want you to use it is an auth system and I will have to store user data but is there a way I can use the existing nodebb data so the users don't have to make separate accounts and can login with their already existing nodebb accounts and then I just save their data as a new user. I have been searching the forums for an answer but it seems most cases are either starting a new app and nodebb forum or have an existing auth system and addidng nodebb